Results: In a consecutive series of 301 ACL reconstructions, 50 patients (33 male, 17 female) with a mean age of 29.6 years (range, 14-61 years) were diagnosed with a medial meniscal ramp lesion at . hypoplastic meniscus was not the cause of the patients pain, suggesting There Type 1 is most common, and type The patient underwent an all-inside lateral meniscus repair. Source: Shepard MF, et al.
How I Diagnose Meniscal Tears on Knee MRI : American Journal of The sagittal proton density-weighted image (2A) demonstrates increased signal intensity at the periphery of the medial meniscus posterior horn (arrow) but no fluid signal on the sagittal T2-weighted image (2B) and no gadolinium extension into this area on the MR arthrogram sagittal fat-suppressed T1-weighted arthrographic image (2C) consistent with a healed repair. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) Type It is important to know the age of the patient when interpreting the MRI. Direct MR arthrography requires intraarticular injection of 20-50 mL of dilute gadolinium contrast prior to imaging which distends the joint capsule and offers a high signal to noise ratio on T1-weighted images with contrast extension into the meniscal substance indicating a recurrent tear or an unhealed repair. In this case, having the prior MRI exam is useful for showing the location of the initial tear and the new tear in a different location. Posterior root repair (Figure 16) is being performed with increasing frequency and has been shown to have better outcomes and decreased risk of osteoarthritis compared to posterior root tears treated non-operatively. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. meniscus is partial meniscal excision, leaving a 6- to 7-mm peripheral For root tears in general, sagittal imaging may demonstrate a meniscal ghost sign. runs from the anterior horn of the medial meniscus to either the ACL or found that the absence of a line of increased signal through the meniscus extending to the articular surface on proton density and T2-weighted images was a reliable MRI finding for an untorn post-operative meniscus with 100% sensitivity. Meniscal transplants can fail at the implantation site by avulsion, failure of bone plug incorporation or bone bridge fracture. Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. Problems encountered in a discoid medial meniscus are the same as a In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). It is located in the lateral portion of the knee interior of the knee joint. High signal close to fluid intensity contacts the tibial surface on the sagittal T2-weighted image (11B) and is equivocal. The intrameniscal ligament where it diverges from the back of the anterior horn of the lateral meniscus is also a common area misinterpreted as a tear. Regardless of the imaging protocol chosen for evaluation of the postoperative meniscus, optimal imaging interpretation includes: The normal MRI appearance after partial meniscectomy is volume loss and morphologic change, commonly truncation or blunting of the meniscal free edge. A 64-year-old female with no specific injury presented with knee pain, swelling, and locking that she first noticed after working out at the gym. Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. An intact meniscal repair was confirmed at second look arthroscopy. However, few studies have directly compared the medial and lateral root tears. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus.
At second look arthroscopy, the posterior horn tear was healed and the anterior horn tear was found to be unstable and treated by partial meniscectomy. The most common location is the anterior horn-body junction of the lateral meniscus and less commonly in the mid posterior horn or root of the medial meniscus. : Complications in brief: arthroscopic partial meniscectomy. The purpose of our study was to determine if cysts of the ACL are the origin of cysts adjacent to the AHLM. This mesenchymal an adult), and approximately twice the size of the anterior horn on
Lateral Meniscus - ProScan Education - MRI Online The lateral meniscus attaches to the popliteus tendon and capsule via the popliteomeniscal fascicles at the posterior horn and to the medial femoral condyle by the meniscofemoral ligaments. 2019: Factors associated with bilateral discoid lateral meniscus tear in patients with symptomatic discoid lateral meniscus tear using MRi and X-ray Orthopaedics and Traumatology Surgery and Research: Otsr 105(7): 1389-1394 MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. It is possible that there could have been some tears missed at arthroscopy that were on the undersurface of the anterior horn, an area which is extremely difficultif not impossibleto visualize. The patient underwent meniscal repair but had recurrent pain prompting repeat MRI 8 months post-operative. Tears 3. History of medial meniscus posterior horn and body partial meniscectomy. Renew or update your current subscription to Applied Radiology. least common is complete congenital absence of the menisci. Klingele KE, Kocher MS, Hresko MT, et al. Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. Meniscus tears, indicated by MRI, are classified in three grades.
Bucket-handle tear of the lateral meniscus: Flipped meniscus sign You have reached your article limit for the month. The aim of this study was to evaluate diagnostic values involved in conventional magnetic resonance imaging (MRI) features of MM posterior root tears (MMPRTs) and find other MRI-based findings in patients with partial MMPRTs. Get unlimited access to our full publication and article library. The lateral meniscus is produced by the varus tension and tibial IR. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. According to these authors, increased signal to the surface on only one slice should be interpreted as a possible tear. Cases of only one abnormal slice correlated to tears at arthroscopy 55 % of the time for the medial meniscus and 30 % for the lateral [, Accuracy of diagnosing meniscus tear with these criteria has been good. Grades 1 and 2 are not considered serious. On examination, the patient had medial joint line tenderness with positive McMurray test. Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. Discoid lateral meniscus in children. This case is almost identical to the previous case with a different clinical history. Also, the inferior patella plica inserts on the
Meniscal Tear Patterns - Radsource Anomalous insertion of anterior and posterior horns of medial meniscus Sometimes T2 signal in a healed tear may look similar to fluid. slab-like configuration on sagittal MR images, with > 3 bowties Note that signal does not contact articular surface, The most common criterion for diagnosing meniscus tear on MRI is an increased signal extending in a line or band to the articular surface. Both horns of the medial meniscus are triangular with sharp points. Discoid lateral meniscus of the knee joint: Nature, mechanism, and operative treatment. However, recognizing these variants is important, as they can The patient had a recent new injury with increased pain. Medial meniscus posterior horn peripheral longitudinal tear treated with repair. anterior horn of the medial meniscus into the anterior cruciate ligament
PDF The Menisci on MRI Pearls and Pitfalls or the Radiology Registrar 17. of these meniscal variants is the discoid lateral meniscus, and the
the menisci of the knees. Medial meniscus posterior horn peripheral longitudinal tear (arrow) seen on the sagittal proton density-weighted image (15A) and managed by repair. A tear was found and the repair was revised at second look arthroscopy. The meniscus is diffusely vascularized in early life but in adults, only 10-30% of the peripheral meniscus is vascularized, often referred to as the red zone. Lateral meniscus bucket handle tears can produce the double anterior horn sign or double ACL sign. Controlling Blood Pressure During Pregnancy Could Lower Dementia Risk, Researchers Address HIV Treatment Gap Among Underserved Population, HHS Announces Reorganization of Office for Civil Rights, FDA Adopts Flu-Like Plan for an Annual COVID Vaccine. Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). of a case of discoid medial cartilage, with an embryological note. A Study of Retrieved Allografts Used for ACL Surgery, Long-Term Results of Meniscus Allograft Transplantation with Concurrent ACL Reconstruction, Anterior Horn Meniscal Tears — Fact or Fiction, How Triathletes Can Use Cycling Cadence to Maximize Running Performance, Pharmacology Watch: HRT - Position Paper Places Benefits in Question, Clinical Briefs in Primary Care Supplement. Meniscus repair is superior to partial meniscectomy in preventing osteoarthritis and facilitating return to athletic activity.11 However, the period of postoperative immobilization and activity restriction associated with meniscus repair is longer than that associated with partial meniscectomy and requires a compliant, motivated patient to be successful. The posterior root of the medial meniscus attaches to the tibia, just anterior and medial to the posterior cruciate ligament (PCL). pretzels dipped in sour cream. By continuing to use our site, you consent to the use of cookies outlined in our Privacy Policy. The trusted source for healthcare information and CONTINUING EDUCATION. Mild irregularities of the meniscal contour may be present, particularly in the first 6-9 months after surgery which tend to smooth out and remodel over time.15 For partial meniscectomies involving less than 25% of the meniscus, conventional MRI is used with the same imaging criteria for evaluating a tear as the native meniscus linear intrasubstance increased signal extending to the articular surface, visualized on 2 images, either consecutively in the same orientation or in the same region in 2 different planes or displaced meniscal fragment (based on the assumption that imaging is spaced at 3 mm intervals). Kocher MS, Klingele K, Rassman SO. morphology but lacks its posterior attachments; ie, the meniscotibial Skeletal radiology. While they can arise from a number of mechanisms, root tears are generally thought to be chronic 5. De Smet A. Magnetic resonance imaging (MRI) of both knee joints showed an almost complete absence of the anterior and posterior horns of the medial meniscus, except for the peripheral portion, hypoplastic anterior horns and tears in the posterior horns of the lateral meniscus in both knees (Fig. On the fat-supressed proton density-weighted coronal (17A) and axial (17B) images, notice the trapazoidal shaped bone bridge (arrow) placed in the tibial slot with menscal allograft attached at the anterior and posterior roots. Special thanks to David Rubin, MD for providing several cases used in this web clinic. MRI plays a critical role in influencing the treatment decision and enables information that would obviate unnecessary surgery including diagnostic arthroscopy. Connolly B, Babyn PS, Wright JG, Thorner PS. On imaging alone, the radiologist may not be able to distinguish a residual tear (failed repair) from a recurrent tear in the same location. Nakajima T, Nabeshima Y, Fujii H, et al. This emphasizes the importance of baseline MRI comparison for evaluation of the postoperative meniscus.3. On medial posterior root tears there is often 2: On posterior root radial tears of the lateral meniscus, the appearance may be similar to radial tears in other locations. Diagnosis of meniscal tears on MRI improves when these guidelines are followed to optimize signal-to-noise ratio: high-field-strength magnets are preferable (1.5 T and stronger); a high-resolution surface coil should be used; the field of view should only encompass the necessary structures and routinely be 16 cm or less; image slices should not be too thick (34 mm); and the matrix size should be at least 256192 or higher [, A normal meniscus is low signal on all sequences. Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12. of the meniscus. How I Diagnose Meniscal Tears on Knee MRI. The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). AJR American journal of roentgenology. The anomalous insertion Diagnostic performance is decreased following partial meniscectomy since the standard criteria used to diagnose a meniscus tear cannot be applied to the post-operative meniscus.3,4,5,6 Partial meniscectomy may distort the normal morphology of the meniscus and increased meniscal signal intensity may extend to the articular surface when a portion of the meniscus has been resected, simulating a tear. On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. The lateral meniscus is one of two fibrocartilaginous menisci of the knee. Kijowski et al.
Posterior Horn Lateral Meniscus Tear | Knee Specialist | Minnesota Kim SJ, Moon SH, Shin SJ. Anterior horn tear of the lateral meniscus in footballers with a stable knee is characterized by pain at the anterolateral aspect of the knee during knee extension, especially when kicking. Magnetic Resonance Imaging Arthroscopy Orthodontic Extrusion Anterior Cruciate Ligament Reconstruction Arthroscopes Suture Anchors Tissue Culture Techniques Tissue Engineering Injections, Intra-Articular Range of Motion, Articular Arthrography Hardness Tests Orthopedic Procedures
Flipped meniscus - anterior horn lateral meniscus | Radiology Case Pinar H, Akseki D, Karaoglan O, et al. Following a meniscal repair procedure, the meniscus can be categorized as healed if there is no fluid signal in the repair, partially healed if fluid signal extends into less than 50% of the repair site, or not healed if fluid signal extends into greater than 50% of the repair site. Magnetic resonance imaging (MRI) revealed an elongated free edge of the diffusely enlarged lateral meniscus extending toward the intercondylar region on coronal T1-weighted images (Figure 1A). In this case, we can determine that there is a new tear in a different location. Congenital discoid cartilage. mimicking an anterior horn tear. sagittal magnetic resonance (MR) images. Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Posterior Instability and Labral Pathology, Imaging Evaluation of the Painful or Failed Shoulder Arthroplasty, Other Entities: PLRI, HO, Triceps, and Plica, MRI-Arthroscopy Correlations in the Overhead Athlete, Acetabular Fossa, Femoral Fovea, and the Ligamentum Teres.
Meniscus | Radiology Key On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. Conventional MRI imaging correlates well with arthroscopic evaluation of the transplants for tears of the posterior and middle thirds of the meniscus allograft with a high sensitivity, specificity and accuracy, but results were poor for evaluation of the anterior third with a low specificity and accuracy.16 Allograft shrinkage and meniscus extrusion are common findings on postoperative MRI but do not always correlate with patient pain and function. At the time the article was created Yuranga Weerakkody had no recorded disclosures.
What is anterior horn of meniscus? - KnowledgeBurrow.com On MR images of the knee it is sometimes impossible to determine with confidence if a focus of high signal in the meniscus is confined to the substance of the meniscus or if it extends to involve the surface. After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI.
Lateral Meniscus Root Tear and Meniscus Extrusion with Anterior horn of the lateral meniscus, and oblique tear orientation In the present study, the patients analyzed came from the have been the most difficult for imaging planes to visualize same geographical area . 7.2 Medial and Lateral Menisci Medial meniscus is larger than the lateral meniscus and is more "open" (=less C-like) and less wide. Monllau J, Gonzalez G, Puig L, Caceres E. Bilateral hypoplasia of the medial meniscus. AJR Am J Roentgenol 2009;193:515-523. rim circumferentially, anteriorly, and posteriorly,19 which Conventional MRI imaging of the postop meniscus offers a noninvasive evaluation of the knee, but postoperative changes can mimic a recurrent or residual meniscus tear. mobility, and a giving-way sensation.11, 15, 16 A high percentage of cases present with an associated meniscal tear and peripheral rim instability.9,16,17 Although discoid lateral meniscus is commonly bilateral, symptoms tend to occur on one side.15 It is characterized by an excess of meniscal tissue with a slab-like configuration in the 2 most common forms (Figure 5). of the AIMM into the ACL is classified as Type 1 (inferior third), Type 2 CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated.
Download Musculoskeletal MRI by Nancy Major, Mark Anderson discoid lateral meniscus, including a propensity for tears to occur and As DLM is a congenital anomaly, the ultrastructural features and morphology differ from those of the normal meniscus, potentially leading to meniscal tears. A previous study by De Smet et al. 2012;20(10):2098-103.
Cysts of the anterior horn lateral meniscus and the ACL: is there a This injury is biomechanically comparable to a total meniscectomy, leading to compromised hoop stressesresulting in decreased tibiofemoral contact area and increased contact pressures in the involved compartment.These changes are detrimental to the articular cartilage and . However, the tear changes plane of orientation over its course. occur with minor trauma. AJR Am J Roentgenol. A 2003 systematic review of the literature, in which 29 publications met strict inclusion criteria, demonstrated pooled weighted sensitivity and specificity of 93.3 % and 88.4 % for the medial meniscus and 79.3 % and 95.7 % for the lateral meniscus, respectively [, Most meniscal tears are visible and best seen on sagittal images. Figure 8: Medial oblique menisco-meniscal . View Mostafa El-Feky's current disclosures, see full revision history and disclosures, Flipped meniscus - anterior horn lateral meniscus, Disproportionate posterior horn sign (meniscal tear). horns to the meniscal diameter on a sagittal slice that shows a maximum If a horizontal tear involves a long segment of the meniscus, the central fragment may displace centrally from the peripheral portion of the meniscus [, Bucket handle tears (BHT) often cause pain and mechanical symptoms, such as locking, catching, and giving way [. of the distal femur and proximal tibia, and in the case report of 2013;106(1):91-115. does not normally occur.13. The medial meniscus is asymmetrical with a larger posterior horn. diagnostic dilemma, as the AIMM band will be seen to extend to the Choi S, Bae S, Ji S, Chang M. The MRI Findings of Meniscal Root Tear of the Medial Meniscus: Emphasis on Coronal, Sagittal and Axial Images. Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. When it involves the posterior root, medial root tears are easier to diagnose than lateral root tears. This is a critical differentiation because the latter represents meniscal tears that can be 5. Extension to the anterior cortex of . Longitudinal medial meniscus tear managed by repair (arrow).
Coronal extrusion of the lateral meniscus does not increase after Long-term outcome after arthroscopic meniscal repair versus arthroscopic partial meniscectomy for traumatic meniscal tears. This high rate of success, however, may not apply to anterior horn tears, which occur much less commonly than posterior horn and meniscal body tears. As visualized on sagittal MR images, the anterior horn of the medial meniscus is shorter than the posterior horn, whereas the anterior and posterior horns of the lateral meniscus are of equal length. Clinical imaging. Complete radial tears, root tears and large partial meniscectomies result in markedly increased contact forces at the articular surface; and in this case, full-thickness chondral loss and subchondral fractures on both sides of the joint.
Which meniscus is more likely to tear? published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). Absence of the meniscus results in a 200 to 300% increase in contact stresses on the articular surfaces.8The meniscus has a heterogeneous cellular composition with regional and zonal variation, with high proteoglycan content at the thin free edge where compressive forces predominate and low proteoglycan content at the thicker peripheral region where circumferential tensile loads predominate. Heron, D, Bonnard C, Moraine C,Toutain A. Agenesis of cruciate Radiographic knee dimensions in discoid lateral meniscus: Comparison with normal control. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome.
PDF Coronal extrusion of the lateral meniscus does not increase after Stay up to date with the latest in Practical Medical Imaging and Management with Applied Radiology. Following partial meniscectomy, the knee is at increased risk for osteoarthritis. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Repair techniques include inside-out, outside-in or all-inside approaches. The example above illustrates marked degenerative changes caused by loss of meniscal function. Diagnosis of recurrent meniscal tears: prospective evaluation of conventional MR imaging, indirect MR arthrography, and direct MR arthrography. Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). Rohren EM, Kosarek FJ, Helms CA. The MRI revealed a vertical flap (oblique) tear of the medial meniscus. tissue only persists at the edges, where differentiation into the There is no universally accepted system for classifying meniscal tear patterns. Youderian A, Chmell S, Stull MA. 2012;199(3):481-99. The medial meniscus covers 60% of the medial compartment. Associated anomalies in a discoid medial ligament will help to exclude these conditions.5 In the first
Lateral Meniscus Tear | Symptoms, Causes and Diagnosis Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients.9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion.10. Discoid medial menisci are much less common than discoid lateral menisci,24 and they may be bilateral. 6. Anomalous Type 1: A complete slab of meniscal tissue with complete tibial coverage. bilaterally absent menisci reported by Tolo et al,3 the intra-articular structures at 8 weeks gestation.
Anterior Horn Meniscal Repair Using an Outside-In Suture Technique In The meniscus can separate from the joint capsule or tear through the allograft. 2006;239(3):805-10. The posterior root of the lateral meniscus (PRLM) attaches along the posterior aspect of the intercondylar eminence of the tibia (Fig.
Bucket Handle Meniscal Tear - Diagnosis - MRI Online